Evolution and Systematics

Evolution

Discussion of Phylogenetic Relationships

The traditional order Gruiformes is not a natural group, and scientists have been detaching families from it for some time, starting with Pedionomidae (plains wanderer) to Charadriiformes, then Turnicidae (buttonquail) also to Charadriiformes. Recently Cariamidae (seriemas), Otididae (bustards), Mesitornithidae (mesites), Rhynochetidae (kagu), and Eurypygidae (sunbittern) have also been remove from the order. Their true relationships are not clear except that the latter two form a clade.

What remains is the core of Gruiformes, the former suborder Grues, which show close affinities in both morphological (Cracraft, 1982; Livezey, 1998) and DNA (Sibley and Ahlquist, 1990; Houde et al., 1997; Fain et al., 2007, Hackett et al. 2008) comparisons. Relationships here are based on Hackett et al. (2008).

The traditional family Rallidae is paraphyletic, since one unusual rail genus, Sarothrura (flufftails, here elevated to family level) is more closely related to Heliornithidae (finfoots) than to typical rails.